package com.knight.sychronized;

import java.util.concurrent.ConcurrentHashMap;

public class APP {
    public static void main(String[] args) {
        synchronized (APP.class){
            ConcurrentHashMap<String,String> concurrentHashMap = new ConcurrentHashMap();
            concurrentHashMap.put("1","tom");
            concurrentHashMap.get("1");
        }
    }
}
